Air compressor



April 14, 1931. E. T. HEWITT ET AL AIR COMPRESSOR Filed Sept. 20, 1929 2 Sheets-Sheet l c a alawlc/ BY a QM 234634 r W 3W4 ATTORNEYS.

April 14, 1931. E. T. HEWITT ET AL 1,300,631

AIR COMPRESSOR Filed Sept. 20, 1929 2 Sheets-Sheet 2 lllll l lgl llllllll ll ll1,

T TORNEYS.

Patented Apr. 14, 1931 PATENT OFFICE UNITED STATES EDWARD r. nnwrrr- AND WILLIAM A. HEWITT, or San rnanersco, CALIFORNIA- AIR COMPRESSOR Application filed September 20, 1929. Serial No, 393,941.

This invention relates to an air compressor or the like, and especially to a structure 'or attachment whereby an ordinary internal combustion engine or motor may be converted H to operate as a-compressor.

The object of the present invention is to provide a valve head which is adapted to be interposed between the cylinder and head of an ordinary gas engine, whether of the single 1 or multiple type, and when so interposed causes conversion of a gas engine into an air compressor; to provide a valve head which permits the use of ring or disk valves; to provide a valve head in which the valves are adapted to be concentrically grouped in pairs, one pair for each cylinder, and further to provide a novel valve cage structure whereby the valves and cooperating sprlngs may be quickly removed with relation to the valve head, for inspection, repair etc.

One form which the invention may assume is shown by way of illustration in the accompanying drawings, in which:

1 is a side elevation of the compressor, partially broken away and partially in section.

Fig. 2 is a vertical cross section of the upper portion of the compressor,

Fig. 3 is a plan view of the' compressor, partly broken and partially shown in section.

When constructing a compressor such as we are illustrating practically any type of gas engine or motor having a removable head may be employed. In the present instance we have illustrated a Fordson tractor motor, as this has proven very suitable for conversion to a compressor. When converting a motor of thistype, the cam shaft, together withthe inlet and exhaust valves, pusher rods, springs etc.,' are removed and the valve stem guides 2 are plugged or closed by any suitable means, such as the bolts shown at 3. The head of the motor, generally indiinterposed between the cylinders C and the head A cated at A, is raised and a valve head B is passing through the head A. The valve head conforms to the shape of the upper end of the cylinders, and air inlet ports are formed therein, as indicated at 4 and 5, to register with the inlet and exhaust valve ports 6,

tervals by means of the inlet and exhaust valves. Inthe present instance, however, the inlet and exhaust valves, together with their actuating mechanism is entirely removed and all of the pockets indicated at 7 and 8 may serve as inlet passages for air or other fluid medium to be compressed.

As it is usually desirable to filter the air before admitting it to a compressor, a mani-' fold such as indicated at 9 is employed. This communicates with the several pockets 7 and 8, and it is provided with one or more inlet openings, such as shown at 10 so as to ermit the insertion of an air filter if desired Formed in the valve head B, in alignment with the pockets or ports 7 and 8, are ports 8 such as indicated at 11. These communicate with the pockets 7 and 8 at the lower end and at'their upper ends with recesses, such as shown at 12, which are formed in the head A. These recesses are ordinarily known as the combustion space. The valve head B is otherwise provided with openings 13, for the reception of valve cages generally indicated at D, there being one valve cage centrally disposed above each cylinder.

The valve cage is best illustrated in Fig. 2. It consists of. an annular ring shaped memher 14, the bottom portion of which is flanged as at 15to engage anannular seat 16, in the lower face of the valve head, and to form a horizontal annular shoulder 17, for the reception of a ring or disk shaped valve 18. This valve will hereinafter be referred to as the exhaust valve. I

The inner and upper end of the valve cage is threaded to receive a' lock nut 19. This lock nut has a valve seat formed on its lower face, and supports a'n'inletvalve 20, which is also ring. or disk shaped. 1 A pluralityof /radially' disposed arms are formed on the lock nut -19,-as at 21, and these support a "central hub member 22,- which supports a bolt 23, the lower end of which is enlarged 1 toform a head member 24, which carries a 9 number of springs to normallyhold the inlet valve 21 on its seat,

25. These springs (serve and similar springs 26 serve; the function of holding the exhaust valvell8 on its seat.

. Communication with the central openings 13 thereto as desired.

In actual operation it will be understood 1 that the crank shaft30 of the motor, together with the connectin rods 31, and pistons 32 I are left intact. It is accordingly only necessary to drive the ,crank shaft in any manner desired. During the revolution of the crank shaft, pistons 32 will reciprocate. During their downward strokes, air will be drawn' through the manifold 9, the valve pockets- 7 and 8, and the orts 6 and 11, into the recessesformed in t e lower face of the head A.

From here the air, passes downwardly between the radial arms of the lock nut 19, and pass the valve 21 into the cylinder. During I 35 the up-stroke' of the piston the spring 25 4 closes the inlet valves 21 and as the; pressure I builds-up, the exhaust valves 18 are lifted from their seatsand the compressed. air or 1 fluid forced through the passages 27 into 40 the discharge manifolds 28, from where it .may be conveyed into storage tanks, or what ever the case may be. r

- It is well known that theefiiciency' of a compressor, particularly where fairly'high pressuresare required, 1s larged dependent upon the clearance specs formed between the. top

of the piston w of its stroke'and the valve mechanism.

. By constructing a valve such as here shown, 5 and placing the valves in the cage as here illustrated, the clearance s ace may be re-.' duced to a'minimum and high pressure volumetric efliciency may. be obtained.

. Volumetric efliciency is further increased by the unrestricted flow of air into the inlet valves, this bein due to the fact that both the exhaust an inlet ports formerly employed.- may, in this instance, be utilized for the admission of air. In other words, the

enclosed air has a free and unrestricted flow direct-to theinlet valve and drawings and attenuation ofthe air is revented.

Leakage losses-around t e valve-cage are also. prevented as a packing gasket such as ndicated at 16c may be interposed between enit reaches the upper end,

a similar gasket may be interposed at the point indicated at 19a. That is, below the lock nut.- These are the only two points where leakagecould possibly take place and the interposition of gaskets at these points positively prevents leakage.

The valve cages are secured by the lock nuts 19, and by no other means, and 1t 1s thus possible, when the head A is removed, to quickly'and readily remove any or all of the valve cages as the case may be-th1s being 1mportant when inspection and repalr are considered. I p I The mechanism" as a Whole is accordingly simple. In fact, the only mechanism n- -volved is the valve head B, with the valve cages mounted therein. This is merely 1nterposed between the cylinders andthe head of the motor, and when secured-by the stud bolts'in the usualmanner, is ready for operation, it being understood that the exhaust and inlet valves of theengine, together with the1r actuating mechanism has been removed.

i The free circulation of inlet air aroundthe valvehead is also important, as it tends to maintain the tem erature fairly low. The

head A and the cy inders proper are however,

water jacketed, and before circulation of water is maintained, practically any temperature desiredmay result. v

While the present invention is descr bed and illustrated in conjunction with a Fordson tractor motor, it is obvious that anordinary Ford automobile motor, and in fact practically any motormay be converted by the use of'a valve head such as here shown.

' The'only change in the valve head would be a different arrangement of the ports 7 and 8 to conform with the inlet and exhaust ports of the motor, and while other features of the inventionare more or less specificallydescribed, we wish it understood that various changes may be resorted to within the scope of the appended claims. Similarly, that the materials and finishes of the several parts employed may be 'such as the manufacturermay decide, or varying conditions orfuses may demand.

Having thus described our inventlon, what we claim and desire to secure by Letters Patent isE- 1. 'A device of the character described comprising a cylinder, an inlet port formed in the c linder, a valve head forming a closure for the cylinder-and having a port formed therein in communication with the inlet port of the cylinder, a valve cage carried, by the valve head, exhaust and inlet valves carried bythe cage, a head member covering the valve head, said head having a recess formed there-, in in communication with the inlet valveand with the inlet ports, and said valve head having a port-formedtherein in communication with the exhaust valve.

2. A device of the character described comprising a block having a plurality of cylinders formed therein, a plurality of inlet ports formed in one side of the cylinder, a valve head forming a closure for the upper end of the cylinder, said valve head having ports formed therein in communication with the cylinder inlet ports, a plurality of valve cages mounted in the valve head, each cage aligning with a cylinder, exhaust and inlet valves carried by each cage, a head member forming a cover for the valve head, said valve head having a plurality of recesses formed therein, which communicate with the inlet ports and the inlet valves, and said valve head having a plurality of discharge ports formed therein communicating with the respective exhaust valves.

3. In a device of the character described a valve head, a plurality of aligned interspaced circular openings formed in the head and extending through the same, said head also having a pair of-inlet ports formed therein for each of said openings, and said head also having ,a plurality of exhaust ports formed therein one for each of said openings, and in communication therewith, a valve cage disposed in each opening and an exhaust and inlet valve in each cage.

4. In a device of the character described a valve head, said head having a plurality of aligned interspaced circular openings formed therein and extending therethrough, said a head also having a plurality of exhaust ports formed therein, one port for each opening and communicating tierewith, a valve cage disposed in each opening, an exhaust and an inlet valve in each cage, said exhaust valves communicating with the exhaust ports only.

EDWARD T. HEWITT. WILLIAM A. HEWITT. 

